import java.lang.*;

// Node Class
class Node
{
  int data;
  Node next, prev;

    Node (int x)		// parameterized constructor
  {
    data = x;
    next = null;
    prev = null;
  }
}

class Main
{
  static Node insertEnd (Node head, int data)
  {

    // Creating newNode memory & assigning data value
    Node newNode = new Node (data);

    // assign data
    // since this will be the last node its next will be NULL
      newNode.next = null;

    //if we are entering the first node
    if (head == null)
      {
	head = newNode;
	newNode.prev = null;
	return head;
      }

    Node last = head;

    // traverse to the current last node
    while (last.next != null)
      last = last.next;

    // assign current last node's next to this new node
    // assign new node's previous to this last node
    last.next = newNode;
    newNode.prev = last;
    // new_node becomes the last node now

    return head;
  }


  static void printList (Node temp)
  {

    Node end = null;
    //as linked list will end when Node reaches Null

    System.out.print ("\nIn forward: ");
    while (temp != null)
      {
	System.out.print (temp.data + " ");
	end = temp;
	temp = temp.next;
      }
    System.out.print ("\nIn backward: ");

    while (end != null)
      {
	System.out.print (end.data + " ");
	end = end.prev;
      }
    System.out.println ();
  }

  // required for insertAfterPosition() method
  static int getLength (Node node)
  {
    int size = 0;

    // traverse to the last node each time incrementing the size
    while (node != null)
      {
	node = node.next;
	size++;
      }
    return size;
  }

  public static void main (String args[])
  {
    Node head = null;
    head = insertEnd (head, 3);
    head = insertEnd (head, 2);
    head = insertEnd (head, 1);
    head = insertEnd (head, 5);
    head = insertEnd (head, 4);

    printList (head);

  }
}

Output

In forward: 3 2 1 5 4 
In backward: 4 5 1 2 3